The region’s ambulance service has more than doubled its spend on private ambulances in just one year because of staff shortages and rising demand, new figures reveal.

Data collected by the Press Association shows the East of England Ambulance Service NHS Trust (EEAST) splashed out more than £14 million on independent ambulances to respond to 999 calls in 2016/17, up from £6.6m the year before.

EEAST was the second highest spender of all 10 NHS ambulance trusts in England during the last financial year.

Tim Roberts, manager of UNISON in the eastern region, said trusts were using private ambulances “out of desperation”.

Speaking to this newspaper, Mr Roberts said: “All ambulance services should be doing everything they can to recruit and retain their staff and therefore there will be less need to buy in expensive additional private ambulances where their staff often have less training and are in poorer quality vehicles.

“They are doing it out of desperation. No-one in a trust would think it’s ideal to use these organisations.”

Mr Roberts said ambulance staff were leaving the NHS because of low wages and he called for the 1% cap on pay rises to be scrapped.

He added: “Unless there is a significant push on retention and recruitment the situation will only get worse.”

Jonathan Street, spokesman for the College of Paramedics, said stress and heavy workloads were leading to high turnovers of NHS staff.

The Royal College of Emergency Medicine’s president, Dr Taj Hassan, said paramedics were being held-up with patients in busy A&E departments, which delayed them from getting back on the road.

Dr Hassan said: “It is concerning that trusts are having to use part of their budget for private ambulances, and serves to highlight the current levels of demand emergency departments are facing.

“Under-resourced departments are struggling with overcrowding and ‘exit block’, when patients cannot be moved in a timely manner to a ward.

“This means patients are waiting longer to be seen and ambulances cannot offload patients quickly, because there is simply no room for them.

“Ambulances then have to queue outside emergency departments for longer than should be necessary, delaying them from getting back out into the community, and creating a need for private ambulances.”

Private ambulances are hired from non-NHS firms and charities, such as St John Ambulance and Thames Ambulance Service, which, like NHS trusts, are monitored by the Care Quality Commission.

A spokeswoman for the EEAST said it had cut down spending on private ambulances to £1.7m in the first five months of 2017/18 by employing more staff.

She added: “Recruiting trained staff, particularly registered paramedics, is extremely challenging and whilst we continue to recruit and train a significant number of patient facing staff we continue to use private ambulance services so that we can respond to patients as quickly as possible and give them the best possible service.”